Battle of Thapsus, April 46 BC

The battle of Thapsus (April 46 BC) saw Caesar defeat the last major Republican army, commanded by Metellus Scipio, after a campaign in Africa which often saw him outnumbered and short of supplies. His victory at Thapsus ended any real chance of a Republican victory in the Civil War, although he had to fight one more campaign in Spain.

The Campaign

After the battle of Pharsalus (48 BC) the defeated Republicans scattered. Some gave up and accepted Caesar’s pardons (including Cicero). Others fled to North Africa. Pompey the Great headed for Egypt, expecting to gain support from Ptolemy XIII, the son of Pompey’s ally during his time in the east. Instead Pompey was murdered as he landed. Cato fled to Cyrenaica, to the west of Egypt, where he hoped to be joined by Pompey. Metellus Scipio, who had fought at Pharsalus, fled to the Roman Province of Africa, where he took command from the existing Republican governor, Publius Attius Varus. Cato moved west to join Scipio. The Republican commanders also included the able Labienus, who had once served under Caesar, but was now probably the military commander of the last major Republican army.

At this point the Romans only ruled a small part of the North African coast. The province of Africa had been established in the aftermath of the final defeat of Carthage, and largely consisted of modern Tunisia. It was surrounded by the Kingdom of Numidia, then ruled by King Juba I. When the Republicans arrived in North Africa, Juba sided with them, and provided intermittent military aid. However he would repeatedly be distracted by the activities of his western neighbours, Bocchus II, king of Mauretania, his brother Bogud and a Roman adventurer, P. Sittius.

If Caesar had moved quickly against them, the Republics would probably had struggled to put up any serious resistance, but instead he became bogged down in Alexandria. He arrived in the city just after the death of Pompey, and soon became involved in Egyptian politics, siding with Cleopatra against her brother-husband Ptolemy. Caesar ended up being besieged in Alexandria (August 48 BC-January 47 BC) for months, a delay that gave the Republicans time to raise a sizable army, gather their fleets, get in touch with Caesar’s opponents in Spain and possibly even plan an invasion of Italy. By the time Caesar arrived in Sicily at the start of the campaign Scipio commanded ten legions, 120 elephants and large fleets, while Juba had four legions and a large number of light troops. The Republican forces were concentrated in the northern part of the province, with their HQ at Utica (to the north-west of the former site of Carthage), and a strong garrison at Hadrumentum (Adramentum), half way down the coast to the south of Carthage.

Our most detailed account of this war comes from the African Wars, officially written by Caesar as part of his long series of commentaries on his wars, but probably actually written by one of his officers. This is one of the few ancient sources to provide frequent dates, so we even have some idea of the timescale of the campaign.

After defeating the Egyptians at the battle of the Nile Caesar moved north into Asia Minor. There he defeated Pharnaces (the son of Mithridates the Great) at Zela, ending a potentially dangerous invasion of Roman territory. He then returned to Italy, where he attempted to undo the damage that had been caused by Mark Antony, who he had left in command at Rome. He then turned his attention to the Republicans in North Africa.

Caesar left Rome in December 47 BC, and reached Lilybaeum on Sicily in mid-December (the 14th day before the calends of January 46 BC, the calends being the first day of the month). He ordered his armies to muster on Sicily, and within a few days had six legions.

Once the first six legions had arrived, Caesar embarked them on his transport ships. He set sail for Africa on the sixth day before the Calends of January, and arrived off the African coast two days later. However during this short journey his fleet became badly scattered, so he only had a handful of galleys with him. This would cause him a great deal of difficulty, and the first part of the campaign would be dominated by Caesar’s attempts to gain a firm foothold somewhere in Africa and gather the rest of his fleet.

Caesar reached the North African coast near the end of Cap Bon. He sailed south, passing Clupea (the Carthaginian city of Aspis), near the eastern tip of the cape, and Neapolis, and then arrived off Hadrumentum. He landed near Hadrumentum, although at this point he only had 3,000 infantry and 150 cavalry with him. The city was defended by two legions, so Caesar didn’t risk an attack on it. One of Caesar’s officers did attempt to open negotiations with C. Considius, the Republican commander in the city, but without success. Caesar spent one day outside Hadrumentum, but he wasn’t yet strong enough to besiege the city. He thus decided to head south to Ruspina (probably on the sight of modern Monastir, ten miles to the south-east). The garrison attacked his troops as they began their march, but the attack was repulsed and Caesar reached his new base safely late on 1 January 46 BC.

After establishing himself at Ruspina, Caesar moved a short distance down the coast to Leptis Minor, where the citizens submitted to him. Some of his missing ships arrived while he was at Leptis, and he discovered that a large part of his fleet had decided to head for the Republican HQ at Utica. Caesar unloaded his troops and sent the empty ships back to Sicily to bring reinforcements, while ten galleys were sent to try and find the remains of the first wave.

Caesar only stayed at Leptis for one day, returning to Ruspina on the following day (given as the third day before the nones of January or the 2nd).

At this date the port of Ruspina was two miles outside the city. Caesar left part of his army in the city and led seven of his veteran cohorts to the port, causing some concern amongst the less experienced troops left in the city. Caesar’s plan was to use his elite troops to man part of his fleet, which he was going to lead to see to find the missing part of his fleet. However after spending one night onboard ship, the missing fleet turned up. Caesar was thus able to abandon his planned naval expedition and return to Ruspina.

Soon after this lucky break Caesar suffered his first defeat in Africa. He was clearly still short of supplies, as he decided to lead thirty cohorts on a foraging expedition. This small army ran into a larger Republican force, commanded by Labienus and the rather obscure ‘two Pacidii’. Although the African Wars attempts to put a positive spin on events, Caesar was clearly defeated and forced to retreat back to his base (battle of Ruspina). This action is dated to the day before the nones, the 4th of January 46 BC).

Caesar now began to seriously fortify his position. He improved the fortifications of his camp, and linked both his camp and the city of Ruspina to the sea with lines of fortifications, creating a defended zone. He landed many of the heavy weapons carried by his warships, along with many of the sailors and the archers of the fleet, and used them to reinforce his cavalry. He also set up workshops to manufacture more darts, arrows, sling bullets and palisades, and sent orders for timber and food to be sent from Sicily.

Caesar’s actions were motivated by the news that Scipio was approaching with eight legions and 3,000 cavalry, to join Labienus. The combined Republican army camped three miles from Caesar’s position. Their cavalry dominated the area around Caesar’s fortified area, making it very difficult for his men to gather supplies. They were soon forced to live off sea weed, washing in fresh water.

Caesar did have one stroke of luck at this time. Juba had decided to come to Scipio’s aid, and left Numidia with a large army. Once he left Bogud of Mauritania and P. Sitius invaded Numidia, besieged and captured Cirta and killed all of the citizens. The news reached Juba just before he reached Scipio, forcing him to retreat with most of his troops. He only left thirty elephants to aid Scipio.

A standoff now developed outside Ruspina. Labienus attempted to capture Leptis, but without success. There were constant cavalry skirmishes between the lines, but no major battle. Scipio repeatedly drew up his army in order of battle, but Caesar refused to rise to the bait and stayed quietly within his camp. During this standoff a number of Numidians deserted to Caesar’s side, apparently because he was related to the great Roman general Marius, who had campaigned successfully in North Africa during the Jugurthine War.

During the same period a deputation arrived from the free city of Acilla (possibly Acholla, south of Ruspina on the coast), offering to submit to Caesar. He agreed to their offer, and sent a small force under C. Messius to take possession. A Republican force under Considius Longus attempted to get there first, but failed. Labienus then sent reinforcements, and Considius began a siege of the city.

Reinforcements now began to reach Caesar. The Thirteenth and Fourteenth Legions, along with 800 Gallic cavalry and 1,000 archers and slingers arrived at Ruspina after a simple four day voyage from Sicily.

Caesar was encouraged by the arrival of these reinforcements. He gathered together all of his legions, and advanced out of his fortified area, along the coast towards a nearby plain bordered by a ridge. He built fortifications on this ridge, close to Scipio’s camp. Scipio and Labienus sent out their cavalry, to a position about a mile outside their camp, supported by a line of infantry half a mile further behind. At first Caesar ignored this force, but when the cavalry got close to his works he sent his Spanish cavalry and some light infantry to drive away the nearest Numidian cavalry. Labienus took the right wing of the main cavalry force forward to support the Numidians, and was nearly caught by Caesar’s counterattack. Labienus escaped, although possibly after suffering heavy losses.

On the following day Caesar drew up his army in order of battle, and advanced inland towards Uzita (somewhere close to Sidi Al-Hani, twenty five miles inland from Ruspina), where Scipio had his supply base. Scipio formed his army up in four lines, ready to defend the town. A standoff then developed, with neither commander willing to risk an attack. This period saw Juba return with three legions, 800 ‘regular’ cavalry, a large number of Numidian cavalry and light troops and 30 elephants. He camped close to Scipio, and encouraged him to act more aggressively. A series of clashes occurred between the lines as Caesar slowly moved his fortifications closer to Uzita, planning to besiege the town. He also received more reinforcements, as the ninth and tenth legions arrived from Sicily. The standoff appears to have continued for some time, and even included at least one occasion when the two armies spent the entire day in order of battle facing each other, without a battle actually taking place.

Eventually Caesar was forced to abandon his attempt to capture Uzita by a shortage of supplies. He placed garrisons in Leptis, Ruspina and Acilla, burnt his camp outside Uzita, and led his main army on a successful foraging expedition, before returning to his camp.

The next activity took place around the town of Zeta, about ten miles from Scipio’s camp and eighteen from Caesar’s. Scipio sent two legions to forage in the area. Caesar attempted to ambush this force, and captured the town. Scipio responded by sending out his entire army, forcing Caesar to retreat. Labienus attempted to ambush Caesar as he passed near Scipio’s camp, and for some time Caesar was in some trouble, unable to make much progress, but eventually he reached the safety of his own camp.

On the twelfth day before the calends of April (21st March), Caesar advanced towards Scipio’s camp and offered battle once again. Once again Scipio refused to be drawn. On the following day Caesar led his army towards Sarsura, where Scipio had a garrison. Labienus attempted to harass the rear of Caesar’s army, but was chased off by detachments from the legions. Caesar captured Sarsura, then moved on to Agar (roughly sixteen miles to the north of Thapsus), where he had previous found supplies.

Once again Caesar received reinforcements, this time 4,000 legionaries, 400 cavalry and 1,000 archers and slingers, many made up of stragglers who had been unable to sail with earlier fleets. Once again this encouraged Caesar to offer battle, this time around the town of Tegea, somewhere close to Scipio’s camp. This time a small scale battle did break out, but Scipio refused to commit his legions.

The climax of the campaign was now approaching. Caesar now realised that Scipio wouldn’t accept battle on Caesar’s terms, and he would have to force him to fight. He decided to take his army to besiege Thapsus, a coastal city about sixteen miles from his camp at Agar. Thapsus contained a Republican garrison under Virgilius, and had been loyal to the Republicans throughout the conflict, even though it was only fifteen miles from Caesar’s main base at Ruspina.

Caesar raised his camp at midnight on the day before the nones of April (4 April 46 BC). His troops began to build siege works on the day they arrived outside the town, as well as building fortifications to guard against any attempt by Scipio to intervene.

Scipio realised that he would have to try and save Virgilius. He followed Caesar, and camped in two camps eight miles from Thapsus (probably one for Juba’s men and one for Scipio’s).

The Battle

There appear to have been two land routes to Thapsus. One ran along a narrow spit of land between the sea and some salt pits and was 1,500 paces long. The second was a more straightforward land route. Caesar built a fort to defend the spit, and placed most of his troops in the siege lines on the second route.

Scipio attempted to advance along the spit, but was stopped by the camp. He spent the following night camped near the salt pits, but on the following morning advanced towards Caesar’s fort and began to entrench himself around 1,500 paces from the sea.

Caesar decided to split his forces. Two legions and part of the fleet were left to continue the siege. The rest of the fleet was sent to get into the enemy’s rear, where at the right moment they were to cause a distraction. Finally Caesar led the bulk of his army towards Scipio’s new camp.

Scipio was warned of Caesar’s advance, and formed his army up on order of battle outside his camp. He posted his elephants on the wings, and left some of his soldiers to continue fortifying the camp.

Caesar responded by drawing his army up in three lines. He posted the Tenth and Second legions on the right, the Eighth and Ninth on the left and five legions in the centre. He posted five cohorts on each wing, facing the elephants and supported by the archers, slingers and lightly armed troops. He then toured his army, reminding his veterans of their many victories and encouraging his fresh levies to emulate them.

According to the African Wars, Scipio’s men were in some disorder. Caesar’s men were eager to get to grips with them, but Caesar wasn’t ready to order an attack. The decision was taken from him when some of the troops on his right forced one of the trumpeters to sound the signal for the attack. The centurions were unable to stop their men, who charged into battle without orders. Caesar realised that he couldn’t stop the attack, and ordered a general assault.

Luckily for Caesar, his impetuous right wing was quickly victorious. They were able to drive away the elephants on Scipio’s left, and with the elephants gone his Mauritian cavalry fled. Caesar’s right wing then turned in and captured Scipio’s camp. The survivors fled towards the camp they had used on the previous day.

The garrison of Thapsus made an attempt to escape from the town, either to support Scipio or to try and flee to safety. They came out of the gate nearest to the sea and attempted to wade past Caesar’s siege lines, but were repulsed by the defenders of the camp.

In the meantime Scipio’s defeated troops fled to their camp, but their officers appear to have deserted them at this point, and they were unable to rally. Caesar’s men engaged in a brutal pursuit, and Scipio’s men fled towards Juba’s camp. However this was already in Caesar’s hands, and the fugitives fled to a nearby hill. They attempted to surrender, but Caesar’s men were still somewhat out of control, and massacred them. They even killed a number of senior men on their own side, causing many of Caesar’s noble officers to flee to his side to seek safety. Caesar attempted to convince his men to accept the surrender of Scipio’s men, but without success. Around 10,000 men were killed on Scipio’s side and the rest of his army fled. According to the African Wars Caesar only lost 50 dead and some wounded.

The Aftermath

In the aftermath of the battle the garrison of Thapsus refused to surrender. On the following day Caesar conducted a parade outside the walls, and then left three legions to continue the siege. Two more were sent to besiege Tisdra, while he led the rest of the army north towards the Republican headquarters at Utica.

The defeated survivors from Scipio’s army fled to Utica, where Cato attempted to rally them. After this failed he arranged ships for their escape, before retiring to his rooms where he committed suicide by stabbing himself with a sword. Although the wound wasn’t immediately fatal, he refused medical attention and died soon afterwards. Caesar was infuriated that he had been denied the chance to pardon Cato, who thus remained forever beyond his mercy.

As he moved north, Caesar was greeted by a series of Republicans begging for a pardon. Caesar happily granted pardons to just about everyone, part of his long term attempt to prove that he wasn’t another Sulla, who had followed his victory in civil war with the infamous proscriptions.

Few of the senior Republican leaders escaped from Africa. Scipio, along with several other senior aristocrats, managed to reach their fleet, but they ran into one of Caesar’s fleets at Hippo Regius (Algeria), and were killed in the resulting naval battle. King Juba found that his countrymen were no long willing to accept him as king, and committed suicide. Labienus and Pompey’s sons reached safety in Spain, forcing Caesar into one final campaign, but his victory at Thapsus effectively ended any serious chance of a Republican Victory. Caesar was back in Rome by mid-summer, and in September held four triumphs - for his victories in Gaul and Egypt and the defeats of Pharnaces and Juba.

How to cite this article:
Rickard, J (29 November 2018), Battle of Thapsus, April 46 BC , http://www.historyofwar.org/articles/battles_thapsus.html